The spinal needle is inserted with a slight cephalad angulation and advanced in the midline (B). If bone is contacted, it may be either the caudad (A) or cephalad (C) spinous process. The needle should be redirected slightly, and if bone is encountered at a shallower depth, then the needle is likely walking up the cephalad spinous process. If bone is encountered at a deeper depth, then the needle is likely walking down the inferior spinous process. If bone is repeatedly contacted at the same depth, then the needle is likely off the midline and walking along the lamina.